# Helpful Formulas for the GED® Science Test

The scope of the GED® Science Test is limited to scientific skills rather than scientific knowledge or memorization. That’s great for you! You don’t have to remember lengthy formulas or concepts, but you need to handle the formulas with confidence. So, even though the formulas you’ll need will be given to you during the test, you’ll need to know *how * to use them. How can you achieve that? First, become familiar with the formulas in the chart below and then try answering the questions on our FREE GED Science test using the formulas for the GED® Science Test that are shown in the chart below.

You definitely will not have to deal with all of these formulas on the test. We’ve just listed all we found it would be even remotely possible to encounter during the test. Try working mainly with those you have seen in your previous GED® prep studies.

## Formulas for the GED Science Test

Category Formula Symbols Comment
General
Science and
Statistics
$$Du=Su \cdot \dfrac{Du}{Su}=Su \cdot CF$$ Du = Desired Unit
Su = Starting Unit
CF = Conversion Factor
Multiple steps may
be needed.
General
Science and
Statistics
$$a \cdot b\% =a \cdot \frac{b}{100}$$ a = any real number
b% = any percent
Remember to simplify
if necessary
General
Science and
Statistics
$$\% = \frac{\vert b-a \vert }{b} \cdot 100= \frac{c}{b} \cdot 100$$ % = % increase or decrease
a = new value
b = original value
c = amount of change

General
Science and
Statistics
$$\overline{x}= \dfrac{\Sigma x_i}{n}$$ $$\overline{x}$$ = mean
$$x_i$$ = value of each measurement
n = number of measurements

General
Science and
Statistics
$$Md=(\dfrac{n+1}{2})^{th} term$$ Md = median
n = number of measurements (odd)

General
Science and
Statistics
$$Md=\dfrac{(\frac{n}{2})^{th} term + (\frac{n+1}{2})^{th} term }{2}$$ Md = median
n = number of measurements (even)

General
Science and
Statistics
$$s=\sqrt{\Sigma(x_i-\overline{x})^2/(n-1)}$$ s = standard deviation
$$\overline{x}$$ = mean
$$x_i$$ = value of each measurement
n = number of measurements

General
Science and
Statistics
$$V=s^2$$ v = Variance
s = standard deviation

General
Science and
Statistics
$$CV=RSD=100 \cdot \dfrac{s}{\overline{x}}$$ CV = Coefficient of variation
RSD = Relative standard deviation
s = standard deviation

General
Science and
Statistics
$$^\circ F$$ = $$^\circ C \cdot \dfrac{9}{5} + 32^\circ$$
or
$$^\circ C = (^\circ F -32) \cdot \dfrac{5}{9}$$
$$^\circ F$$ = Degrees Fahrenheit
$$^\circ C$$ = Degrees Celsius

Physics $$w=m \cdot g$$ w = weight (N)
m = mass (kg)
g = acceleration of gravity ($$\frac{m}{s^2}$$)

Physics $$v=\dfrac{d}{t}$$ v = Velocity ($$\frac{m}{s}$$)
d = distance (displacement) (m)
t = time (s)

Physics $$a = \dfrac{\Delta V}{\Delta t}$$ a = acceleration ($$\frac{m}{s^2}$$)
$$\Delta V$$ = change in velocity ($$\frac{m}{s}$$)
$$\Delta t$$ = change in time (s)

Physics $$v = v_o + a \cdot t$$ v = Velocity ($$\frac{m}{s}$$)
$$v_o$$ = initial velocity ($$\frac{m}{s}$$)
a = acceleration ($$\frac{m}{s^2}$$)
t = time (s)

Physics $$x = x_o + v_o \cdot t + \frac{1}{2}a \cdot t^2$$ x = position (m)
$$x_o$$ = initial position (m)
$$v_o$$ = initial velocity $$(\frac{m}{s})$$
t = time (s)
a = acceleration $$(\frac{m}{s^2})$$

Physics $$v^2 = v_o^2+2a \cdot (x-x_o)$$
v = Velocity ($$\frac{m}{s}$$)
$$v_o$$ = initial velocity $$(\frac{m}{s})$$
a = acceleration $$(\frac{m}{s^2})$$
x = position (m)
$$x_o$$ = initial position (m)

Physics $$f=m \cdot a$$ f = force (N)
m = mass (kg)
a = acceleration ($$\frac{m}{s^2}$$)

Physics $$p=mv$$ p = momentum ($$\frac{kg \cdot m}{s}$$)
m = mass (kg)
v = velocity ($$\frac{m}{s}$$)

Physics $$w = f \cdot d$$ w = work (J)
f = force (N)
d = distance (m)

Physics $$P= \dfrac{w}{t}$$ P = power (W)
w = work (J)
t = time (s)

Physics $$PE_g = m \cdot g \cdot h$$ $$PE_g$$ = Gravitational Potential Energy (J)
m = mass (kg)
g = acceleration of gravity ($$\frac{m}{s^2}$$)
h = height (m)

Physics $$KE = \frac{1}{2} \cdot m \cdot v^2$$ KE = kinetic energy (J)
m = mass (kg)
v = velocity ($$\frac{m}{v}$$)

Physics $$MA = \dfrac{Ld}{Ef} = \dfrac{Ld_d}{Ef_d}$$ MA = Mechanical Advantage
Ef = Effort (N)
$$Ld_d$$ = Load distance (m)
$$Ef_d$$ = Effort distance (m)

Physics $$F_g = \dfrac{G \cdot M \cdot m}{r^2}$$ $$F_g$$ = Gravitational force (N)
G = Gravitation constant ($$6.67 \times 10^-11 N m^2/kg^2$$)
M and m = masses of two bodies (kg)

Physics $$F_b = r_f \cdot g \cdot V$$ $$F_b$$ = Buoyant force (N)
$$r_f$$ = Density of fluid displaced ($$\frac{kg}{m^3}$$)
g = Acceleration of gravity ($$9.8 \dfrac{m}{s^2}$$)
V = volume of fluid $$(m^3)$$

Physics $$V=IR$$ V = potential difference (V)
I = current (A)
R = resistance ($$\Omega$$)
Ohm’s Law
Physics $$\lambda = \dfrac{v}{f}$$ $$\lambda$$ = wavelength (m)
v = velocity of wave ($$\frac{m}{s}$$)
f = frequency $$\frac{1}{s}$$ or Hz

Physics $$Q = m \cdot c \cdot \Delta t$$ Q = Transferred heat (J)
m = mass (g)
c = specific heat capacity ($$\frac{J}{g \cdot K})$$
$$\Delta t$$ = change in temperature (K)

Chemistry $$d=\dfrac{m}{v}$$ d = density ($$\frac{g}{cm^3}$$)
m = mass (g)
v = volume ($$cm^3$$)

Chemistry $$^A_ZX$$ A = Mass Number
Z = Atomic Number = Number of protons
X = Atom symbol

Chemistry $$A=Z+N$$ A = Mass Number
Z = Atomic Number = Number of protons
N = Number of neutrons

Chemistry $$M=\dfrac{m}{n}$$ M = Molar mass ($$\frac{g}{mole}$$)
m = (g)
n = (moles)

Chemistry $$K =$$ $$^\circ C + 273$$ K = Kelvin temperature
$$^\circ C$$ = Celsius temperature

Chemistry $$PV=nRT$$ P = Pressure of gas (units vary)
V = Volume of gas (L)
n = Number of moles (mol)
R = Ideal Gas Constant (units vary)
T = Temperature (K)

Chemistry $$m_r=m_p$$ $$m_r$$ = mass of reactants
$$m_p$$ = mass of products